Think you know SSDs? Think again.

[johngalt]

The SSD Anthology: Understanding SSDs and New Drives from OCZ

The Prelude

I spent about three weeks working on my review of Intel’s X25-M SSD. Most of that was research and writing and re-writing to not only review the product but also to talk about the rest of the SSDs in the marketplace and their deficiencies. Truth be told, I spent more time working on SSDs that weren’t the X25-M than the Intel drive itself. The Intel drive just worked as it should, the rest of them didn’t.
If you read the article, you know I was pretty harsh on some of the SSDs out at the time and if you’ve ever used any of those SSDs, you know why. Needless to say, there was some definite fallout from that review. I’m used to negative manufacturer response after a GPU review, but I’m always a bit surprised when it happens in any other segment.
I took a day or two off after that review went live, I think it was a day. Afterwards, I immediately started working on a follow-up. There was a strange phenomenon a few people noticed, something I unfortunately picked up on after the review went live; if you filled the X25-M up and re-benchmarked it, it got slower. And I had no idea why.
A few weeks later, I had it figured out. But then Nehalem was right around the corner. I’d tackle it after that. But then a new batch of SSDs from OCZ and other vendors were almost ready. I told myself I’d do them all at the same time. Then CES happened.
The More Things Change, The More They Stay The Same

If you look at the SSD market today, you’d assume that it’s very different from what it was just six months ago when the X25-M launched. People are worried that the Intel drive has issues with degrading performance over time. Some vendors are now shipping “revised” JMicron drives with multiple controllers, supposedly fixing all of the problems I talked about last year.
I hate to break it to you guys. As different as the world may seem today, it’s all very much the same.
The Intel drive is still the best of the best. Yes, it, and other SSDs do get slower over time and later in this article I’ll explain why it happens and why it’s not as big of a deal as you’d think. The issues I complained about with the JMicron drives from last year are still alive and well today; they’re just somewhat occluded.
Delay after delay kept me from writing this article, but I believe it’s for the best. What went in to what you’re about to read is nearly six months of research, testing and plain old work with SSDs.
The timing couldn’t be more perfect. We’re about to see a new wave of SSDs hit the market and it’s time to separate the fact from the fiction, the benchmarks from reality and the men from the boys. The last time I wrote an article about SSDs I ruffled quite a few feathers. That’s never my aim, but we’ll see what comes of this one.

Read the entire (long!) article over at AnandTech: The SSD Anthology: Understanding SSDs and New Drives from OCZ

Also, per fakeasdf in the post http://www.sevenforums.com/hardware-devices/6203-think-you-know-ssds-think-again-5.html#post265077 be sure to read the followup.

Here is a snippet:

One Tough Act to Follow

What have I gotten myself into? The SSD Anthology I wrote back in March was read over 2 million times. Microsoft linked it, Wikipedia linked it, my esteemed colleagues in the press linked it, Linus freakin Torvalds linked it.

The Anthology took me six months to piece together; I wrote and re-wrote parts of that article more times than I'd care to admit. And today I'm charged with the task of producing its successor. I can't do it.

The article that started all of this was the Intel X25-M review. Intel gave me gold with that drive; the article wrote itself, the X25-M was awesome, everything else in the market was crap.

The Anthology all began with a spark: the SSD performance degradation issue. It took a while to put together, but the concept and the article were handed to me on a silver platter: just use an SSD for a while and you’ll spot the issue. I just had to do the testing and writing.

But today, as I write this, the words just aren't coming to me. The material is all there, but it just seems so mature and at the same time, so clouded and so done. We've found the undiscovered country, we've left no stone unturned, everyone knows how these things work - now SSD reviews join the rest as a bunch of graphs and analysis, hopefully with witty commentary in between.

It's a daunting, no, deflating task to write what I view as the third part in this trilogy of articles. JMicron is all but gone from the market for now, Indilinx came and improved (a lot) and TRIM is nearly upon us. Plus, we all know how trilogies turn out. Here's hoping that this one doesn't have Ewoks in it.

Read the rest @ AnandTech: The SSD Relapse: Understanding and Choosing the Best SSD

 

[werD]

SSD are freaken awesome.. i just cant wait till i can get 1TB drives for an affordable price

[ame="http://www.youtube.com/watch?v=96dWOEa4Djs&feature=player_embedded"]YouTube - Samsung SSD Awesomeness[/ame]

 

[johngalt]

I'll be 50 by then

 

[Brink]

I would love to have a few of those Intel X25-E drives in a RAID 0. To expensive though.

 

[werD]

meh its like 2bucks a GB of SSD atm... i thought flash drive were expensive... but hell i got a 8GB on my key chain a few 16GBers and like a dozen 4GB-1GBs... but then again i bought them all mostly during black fridays XD

 

[johngalt]

If you read the article, ***all the way through*** you'll understand that for *decent* SSDs you're still more like in the $3-4 range per GB. That's roughly $3000 - $4000 for a TB drive.

 

[werD]

If you read the article, ***all the way through*** you'll understand that for *decent* SSDs you're still more like in the $3-4 range per GB. That's roughly $3000 - $4000 for a TB drive.

aye.. sorry.. little tipsy atm.. had my case of the mundays... i just checked newegg quickly.. personally i havent even seen any 1TB SSD for sale anyways.. besides the lambo laptop with 1TB ssd.. but yeah didnt see the link either and just read the intel review

 

[johngalt]

This review I linked to is long as hell - but it will open your eyes in terms of what you should *really* be looking for when it comes to SSDs, and why it might be a good idea to wait just a bit longer as the technology gets refined, and the *basic* inherent problem with SSDs that conventional HDs *don't* have.

I read all 18 or whatever pages, but the meat is the first 6-8 pages - that is the most important part of the article.

 

[Mark]

Interesting read, thanks John

 

[Jaqie]

Thanks for the article.
All I can say is EW! I've steered clear of SSDs for a long time (electing to buy a lenovo S10 partially specifically because it has a standard 2.5" notebook drive in it) and I was getting close to biting on one now... after this, I say this:
NO thank you! I'm gonna get a few WD black 1TB and be happy.

 

[garysgold]

Thanks JG. Very informative.

Gary

 

[jfar]

Thank You,the article was very interesting,well done.

 

[Everlong]

Interesting read. Interesting to read about the incident OCZ.

Also doesn't make SSDs shine as much with being "the best upgrade" when to keep the performance fast you need to full format every so often.

 

[sid]

its expensive yea .. but be patient they will lower down the prices ..
everything new and good is expensive ..
patience is the medicine !

 

[Deathsink]

Thanks for the article.

 

[johngalt]

its expensive yea .. but be patient they will lower down the prices ..
everything new and good is expensive ..
patience is the medicine !

If you had read the article, you'd see it wasn't the price that is the problem.

 

[ramoine]

Thanks for the info !

 

[garysgold]

Hopefully they'll get that all figured out in the next year±. That should help out on the price too.

Gary

 

[Bare Foot Kid]

Here's the single most important part of the whole article; the more that's written to it the "slower" it'll get.

The Recap

I told you I’d mention this again because it’s hugely important, so here it is:

A single NAND flash die is subdivided into blocks. The typical case these days is that each block is 512KB in size. Each block is further subdivided into pages, with the typical page size these days being 4KB.

Now you can read and write to individual pages, so long as they are empty. However once a page has been written, it can’t be overwritten, it must be erased first before you can write to it again. And therein lies the problem, the smallest structure you can erase in a NAND flash device today is a block. Once more, you can read/write 4KB at a time, but you can only erase 512KB at a time.

It gets worse. Every time you erase a block, you reduce the lifespan of the flash. Standard MLC NAND flash can only be erased 10,000 times before it goes bad and stops storing data.

Based on what I’ve just told you there are two things you don’t want to do when writing to flash: 1) you don’t want to overwrite data, and 2) you don’t want to erase data. If flash were used as a replacement for DVD-Rs then we wouldn’t have a problem, but it’s being used as a replacement for conventional HDDs. Who thought that would be a good idea?

It turns out that the benefits are more than worth the inconvenience of dealing with these pesky rules; so we work around them.

Most people don’t fill up their drives, so SSD controller makers get around the problem by writing to every page on the drive before ever erasing a single block.

If you go about using all available pages to write to and never erasing anything from the drive, you’ll eventually run out of available pages. I’m sure there’s a fossil fuel analogy somewhere in there. While your drive won’t technically be full (you may have been diligently deleting files along the way and only using a fraction of your drive’s capacity), eventually every single block on your drive will be full of both valid and invalid pages.

In other words, even if you’re using only 60% of your drive, chances are that 100% of your drive will get written to simply by day to day creation/deletion of files.

Source


Later :shock: Ted

 

[baarod]

Read the entire (long!) article over at AnandTech: The SSD Anthology: Understanding SSDs and New Drives from OCZ

Next part is out: AnandTech: The SSD Update: Vertex Gets Faster, New Indilinx Drives and Intel/MacBook Problems Resolved

Most important thing to me, since I'll probably never be in the market for Intel's overpriced offering is http://images.anandtech.com/graphs/oczvertexfollowup_033009020937/18688.png

This new Indilinx controller promises not only good performance on paper but an apparently high degree of programability -- recent firmware updates have nearly doubled key performance metrics. And now Super Talent is using the controllers too so it shouldn't be long before I can get a mini pcie version for my eeePC!